Abstract/Project Summary. The goal of cancer screening is to reduce morbidity and mortality through the early detection of disease;but the benefits of screening must be weighed against potential harms, such as false-positive (FP) results, which may lead to increased healthcare costs, patient anxiety, and other adverse outcomes associated with diagnostic follow-up procedures. The overall goal of this research is to develop statistical methods for estimating the cumulative risk of a false-positive (FP) result after multiple rounds of screening in order to facilitate comparative effectiveness research for a variety of screening regimens. Our work will address three specific aims: (1) To describe operating characteristics of existing statistical methods for estimating the cumulative FP risk under scenarios likely to occur in screening mammography;(2) To develop new statistical methods for estimation of the FP risk under dependence of the history of FP results and the screening regimen while incorporating time-varying covariates and allowing for variability among radiologists;(3) To apply new statistical methods to analysis of the FP risk using 13 years of data from the Breast Cancer Surveillance Consortium (BCSC). Under this aim we will analyze data from the BCSC using statistical methods developed under Aim 2 and will carry out comparative effectiveness analyses of the cumulative FP risk after 10 years of annual versus biennial screening, for women beginning screening at age 40 versus 50. This work will allow us to compare the potential harms of proposed breast cancer screening regimens. By contributing information about the potential harms of screening mammography, this work will inform policy-makers and facilitate communication between patients and providers about the risks and benefits of various screening regimens. This will aid both individual decision makers and development of evidence-based guidelines. PUBLIC HEALTH RELEVANCE: Title: Estimating the cumulative risk of a false-positive screening mammogram Project narrative: We propose new statistical methods for estimating the cumulative risk of a false-positive screening mammogram. By contributing information about the potential harms of screening mammography, this work will inform policy-makers and facilitate communication between patients and providers about the risks and benefits of various screening regimens. This will aid both individual decision makers and development of evidence-based guidelines.